Occupancy sensing technologies are used to monitor the presence of occupants in indoor and outdoor spaces. Occupancy sensing systems conserve energy by automatically turning off lighting and other electrical loads when the space is unoccupied or vacant. They may also perform a convenience function by automatically turning on lighting and other loads when an occupant enters a space. An occupancy sensor can include one or more detectors based on any of the numerous different sensing technologies, such as passive infrared (PIR) sensing, ultrasonic (U/S) sensing, audio sensing, video sensing, and the like. The occupancy sensor often includes logic to process signals from the detector and provide an on/off signal that indicates whether the space is occupied or unoccupied. Occupancy sensors also can include a timing device for an “AutoOFF” feature to occur after a last logic event.
An occupancy sensing system generally includes at least two components: an occupancy sensor and a switching device. The sensor generally needs to be positioned in a location that is selected to have a clear view of the entire space that is to be monitored for occupants. Such locations can include ceilings, relatively high on walls, fixtures, or other relatively inaccessible locations.
Positioning the occupancy sensor generally involves mounting the sensor to an electrical box located behind the wall or ceiling surface, and running appropriate electrical wiring through the wall sheathing or ceiling panel from the box to the sensor. A variety of different mounting schemes exist, and the particular scheme used in an individual application often depends on the application, the building, the mounting location, and/or other factor(s). It would be desirable to provide an occupancy sensor with a variety of different mounting features and/or capabilities, thus making the occupancy sensor versatile enough to enable it to be mounted to a wall, ceiling panel, or fixture using any of a plurality of mounting schemes. Such a design would reduce or eliminate the need to manufacture different versions of the sensor (where each version is designed to correspond to a particular mounting scheme).
To provide a further measure of versatility and ease of installation, it would also be desirable to provide an occupancy sensor with a discretely adjustable lens portion that can be used reliably by an installer to adjust the sensor's field of view based on the particular application (e.g., by fine tuning the lens portion to change one or more sensitivity points within a field of view).